视网膜色素变性1基因在常染色体显性遗传视网膜色素变性家系中的突变分析

目的:研究常染色体显性遗传视网膜色素变性(autosomal dominant retinitis pigmentosa,ADRP)家系中视网膜色素变性1(retinitis pigmentosa-1,RP1)基因的突变特征及其在RP发病机制中的作用。方法:运用聚合酶链反应和直接测序方法,对6个ADRP家系的47例成员和50例对照者进行了RP1基因全编码区和邻近剪切位点的内含子区域序列突变的筛选与检测。运用单因素分析、多因素Logistic回归分析研究RP1基因点突变在RP发病中的作用。结果:ADRP家系成员和对照组RP1基因第4外显子上检测出2个变异位点。在1691和1725密码子存在杂合的两种类型的密码子(S1691P,Ser-Pro,TCT→CCT;Q1725Q,Gln-Gln,CAA→CAG)。ADRP家系成员中Ser-1691-Pro及Gln-1725-Gln位点突变率显著高于正常对照组(χ2=11.202,P<0.05)。结论:RP1基因Ser-1691-Pro及Gln-1725-Gln位点多态性可增高RP的危险性,具有潜在的致病性,考虑为ADRP家系的易感基因。     

常染色体隐性遗传视网膜色素变性CNGA1基因突变检测

目的检测常染色体隐性遗传视网膜色素变性患者杆体α—cGMP门离子通道基因（α—cGMP—gated cation channel，CNGA1）基因突变。设计对照性实验研究。研究对象35名常染色体隐性遗传视网膜色素变性（autosomal recessive retinitis pigmentosa，ARRP）家系的先证者和55名散发病例。随机收集100名正常人作为对照。方法采集患者外周血，应用DNA分离试剂盒提取DNA，应用11对CNGA1基因引物进行聚合酶链反应（polymerase chain reaction，PCR），扩增CNGA1基因的全部编码区及内含子外显子的拼接区。利用单链构象多态性（single strand conformation polymorphism，SSCP）技术，将PCR产物进行10％非变性聚丙烯酰胺凝胶电泳，用硝酸银染色，观察有无变异带。如果发现变异带，再将该PCR产物进行DNA测序。主要指标通过PCR，SSCP和DNA测序技术，发现CNGA1基因突变。结果未发现CNGA1基因突变。结论CNGA1基因突变在国人RP患者中的致病情况有待进一步研究。     

Variants of RP1 gene in Chinese patients with autosomal dominant retinitis pigmentosa

BACKGROUND: The objective of this study was to determine the frequency and characteristics of mutations in the RP1 gene and to characterize mutations with the clinical features in the Chinese family with autosomal dominant retinitis pigmentosa (ADRP). METHODS: Forty-three affected, unrelated Chinese individuals with ADRP were recruited between 2002 and 2006. Polymerase chain reaction and direct DNA sequencing were used to screen in the entire coding region and splice sites of the RP1 gene. Cosegregation analysis and population frequency studies were performed for patients with identified mutations. The clinical features were determined by complete ophthalmologic examinations. RESULTS: The mutation detectable rate of the RP1 gene in Chinese patients with ADRP was 1/43. A missense mutation, N985Y, was identified in exon 4 of the RP1 gene in 8 affected individuals from a Chinese family with ADRP. The ophthalmic findings with an N985Y mutation were similar to those of typical retinitis pigmentosa with delayed onset after age 40 years and slow progression. In addition, a total of 9 distinct variants were detected in our study population, most of which were RP1 gene polymorphisms; the pathological significance of P903L, a novel missense mutation, was unconfirmed. INTERPRETATION: Mutations in the RP1 gene are relatively rare in Chinese patients with ADRP. In our cases, N985Y mutation segregated with the phenotype from 1 Chinese family with mild and late-onset ADRP, a finding that has not been documented in other races.     

A novel missense variant in IDH3A causes autosomal recessive retinitis pigmentosa

Background: Inherited retinal degenerations (IRDs) encompass a wide spectrum of genetic ocular diseases characterized by considerable genetic and clinical heterogeneity.

Methods: Complete ophthalmic examination and next-generation sequencing.

Results: We describe a patient with no family history of vision loss, who at the age of 28 years developed visual impairment consistent with a severe form of retinitis pigmentosa. Genetic testing by means of whole exome sequencing identified a homozygous variant in the gene IDH3A. To date, only three papers have reported mutations in IDH3A, in families with early-onset retinal degeneration with or without the presence of macular pseudocoloboma.

Conclusion: This study highlights the importance of including this rarely-mutated gene in the molecular diagnostic set-ups for IRDs, and further delineates the phenotypic spectrum elicited by mutations in IDH3A.     

常染色体显性视网膜色素变性NRL基因的突变研究

目的 对中国人常染色体显性视网膜色素变性（RP）NRL基因的突变现状进行研究。方法 抽取120例RP先证者的静脉血提取DNA。行NRL基因的引物设计合成，PCR扩增，琼脂糖电泳鉴定，异源双连-SSCP电泳。结果 120例散发型RP患者未发现NRL基因突变。结论 中国人RP NRL基因的突变频率很低。     

视网膜色素变性一家系与IMPDH1基因突变相关

目的检测一个常染色体显性遗传性视网膜色素变性家系的IMPDHl基因的突变特征以及与临床表型的关系，探讨其病因和发病机制，利用分子遗传学的方法，确定家系内遗传连锁关系。方法严格按照有关伦理学要求进行家系收集，所有现存家系成员行详细的眼科检查（包括视力检查、裂隙灯和眼底镜检查、视野、暗适应阈值以及ERG检查）。提取该家系lO例患者、lO例未患病成员外周血基因组DNA：应用聚合酶链反应扩增IMPDHl第7外显子基因片段，利用扩增产物直接测序方法对样本进行IMPDHl基因突变检测。结果该家系中lO例患者的IMPDHl基因发生了Asp-226-Asn（GAC→AAC）的错义突变，lO例家系未患病成员则没有此突变。结论IMPDHl基因的一种已知突变Asp-226-Asn与该家系所发生的视网膜色素变性存在紧密连锁关系。     

常染色体隐性遗传视网膜色素变性的相关基因研究进展

视网膜色素变性(rentinitis pigmentosa,RP)是一种发病机制尚未完全明确的遗传性致盲性视网膜疾病,特征性表现为夜盲、进行性视野缩窄和视力下降,眼底可见骨细胞样色素沉着、视网膜血管变细和视盘蜡黄三联症。RP具有较大的遗传异质性和临床异质性,其中常染色体隐性遗传视网膜色素变性(autosomal recessive RP,ARRP)占RP的5%～20%,目前已定位43个致病基因,克隆了其中40个,并且不断有新的相关致病基因被报道。本文就近3a发现与ARRP相关的AGBL5、ARHGEF18、HGSNAT和ZNF408四个基因研究进展作一综述。     

Structural disease progression in PDE6-associated autosomal recessive retinitis pigmentosa

Background and objective: To evaluate the progression of retinitis pigmentosa (RP) caused by mutations in either PDE6A or PDE6B by measuring the progressive constriction of the hyperautofluorescent ring and shortening of the ellipsoid zone (EZ)-line width.

Patients and methods: Fundus autofluorescence (FAF) and spectral-domain optical coherence tomography (SD-OCT) images were obtained from seven patients with autosomal recessive RP caused by mutations in either PDE6A or PDE6B. Measurements of the EZ line width on SD-OCT images and horizontal, vertical diameter, and ring area on FAF images were performed by two independent graders. The measurements of these four parameters were correlated with one another.

Results: We observed that the EZ line width decreased by an average of 91 ± 64 µm per year, while the horizontal and vertical diameters decreased by 103 ± 53 µm and 92 ± 49 µm per year, respectively. The ring area decreased by a rate of 0.3 ± 0.18 mm² per year. Progression rates were similar for the left eye.

Conclusions: We observed a progressive loss of EZ line width and Short-wavelength fundus autofluorescence (SW-AF) ring constriction over time. These results may serve as reference for better prognostic prediction and patients selection for clinical trials promoting cone rescue.     

常染色体显性遗传RP患者视紫红质基因突变的检测分析

目的研究常染色体显性遗传视网膜色素变性（ADRP）患者视紫红质（RHO）基因的突变特征及其在视网膜色素变性（RP）发病机制中的作用。方法应用变性高效液相色谱分析（DHPLC）技术和直接及克隆测序方法对RHO基因进行突变检测。结果一家系4例ADRP患者RHO基因的第297密码子存在杂合的两种类型密码子（AGC和AGT）。该家系的另3名患者未检测到该突变，对照组发现1例此类型沉默型突变。该家系在第3外显子3’端下游第4个碱基处发生C—T转换，其11个成员中该位点呈T纯合子1例，呈杂合子状态8例。对照组发现2例该位点的杂合子状态。结论视紫红质基因Ser-297-Ser突变与RP疾病未出现“共分离”现象，因此该沉默型突变不是该ADRP家系的致病原因，系RHO基因的多态现象。     

IMPDH1基因突变与视网膜色素变性的研究进展

视网膜色素变性(RP)是视网膜感光细胞和色素上皮细胞变性导致的最常见的遗传性致盲眼底病,具有高度的遗传异质性及临床异质性。IMPDH1存在于全身各处器官中。近年来对RP发病机制的探讨已成为研究热点。随着对IMPDH1基因研究的深入,人们发现IMPDH1基因对RP的发病机制研究有着重要意义。对于这种致病基因的结构、突变及其功能目前已有了新的研究进展。本文综述了IMPDH1基因在视网膜色素变性中的最新研究进展。     

常染色体显性遗传视网膜色素变性家系视紫红质基因突变分析

目的:观察常染色体显性遗传视网膜色素变性(autosomaldominantRP,ADRP)家系视紫红质基因(rhodopsin,RHO)的突变特征。方法:抽取11个ADRP家系成员的外周血3～5mL,提取DNA;应用聚合酶链反应(polymerasechainreaction,PCR)扩增RHO基因的第1至5外显子基因片断,对PCR产物进行直接测序。结果:在1个家系中有3例ADRP患者297密码子存在杂合的2种类型的密码子(AGC和AGT)。另外,该家系在第3外显子3'端下游第4个碱基处发生C-T转换,呈T纯合子的1例,8例呈杂合子状态。结论:Ser-297-Ser系基因多态现象。另外,RHO基因第3外显子3'端下游内含子处发生的C/T多态性是否与RP的发生存在相关性,需进一步研究。     

常染色体遗传型视网膜色素变性相关基因的研究进展

视网膜色素变性（RP）是常见的致盲性眼病,具有高度的遗传性和表型异质性。RP致病基因的确立对探讨该病的发病机制、预防和治疗具有重要的意义。近年来,RP的研究有了新的进展,就常染色体显性遗传RP（adRP）与常染色体隐性遗传RP（arRP）相关基因的研究进行综述,归纳其中常见致病基因的作用及其突变发病的可能机制,为RP的研究提供一定参考。     

Unilateral retinitis pigmentosa associated with exfoliation syndrome

Summary A case of a 71-year-old woman showing pigmentary degeneration of the retina associated with posterior subcapsular cataract in one eye, with a normal fellow eye, is presented. Clinical examinations of the patient were performed in order to rule out the various causes which are known to produce funduscopic features that mimic retinitis pigmentosa. Since these investigations were all negative, the fundus changes were interpreted as a unilateral retinitis pigmentosa. One year later, the patient was re-examined and an exfoliation syndrome was discovered in the affected eye, while the fellow eye was unchanged. An association of unilateral retinitis pigmentosa and exfoliation syndrome in the same eye can be regarded as exceptional. The possibility of a correlation of the pathogenetic mechanisms involved in the development of both conditions is discussed.     

常染色体显性视网膜色素变性一家系基因排除定位研究

目的对1个四代常染色体显性视网膜色素变性(autosomal dominant retinitis pigmentosa，ADRP)家系在包含已知ADRP致病基因的全部9条染色体上进行基因连锁定位。方法对家系中的所有患者进行眼科及电生理检查。在家系中对第1、3、6、7、8、11、14、17、19号染色体进行基因扫描、基因型分析及连锁分析。结果在全部9条染色体范围内未发现微卫星位点与该家系疾病表型共分离，最大lod score小于-2。结论此家系中排除了目前已知的所有ADRP位点，此家系中应存在新的ADRP连锁位点位于上述9条染色体之外。     

Mobility performance with retinitis pigmentosa

Purpose : Reduced mobility can have a serious impact on quality of life. Though previous studies have demonstrated that some vision measures relate to the mobility of subjects with simulated and true low vision, the relationship between residual vision and mobility is not clear. We investigated the relationship between clinical vision measures and mobility performance under different illumination levels for subjects with retinitis pigmentosa (RP). Methods : Binocular visual acuities, letter contrast sensitivities and static central threshold visual fields were measured on 10 subjects with RP and nine age-matched control subjects. Mobility performance was measured on an indoor mobility course at high and low illuminances and was assessed by percentage preferred walking speed (PPWS) and number of errors. Results : The RP group showed significantly reduced PPWS and greater numbers of errors than the control group. The reduction in illumination resulted in significantly worse error and PPWS scores. Unlike the control group, the presence of a glare source did not reduce the PPWS of the RP group under high illumination. Multiple regression analyses showed that the average visual field extent was the most significant predictor of mobility; letter contrast sensitivity and visual acuity added to the regression models for the low illumination measures to account for up to 75 per cent of the variation in mobility performance. Conclusions : People with RP have worse mobility than people with normal vision, more so under reduced illumination levels. Visual field extent was the strongest predictor of mobility performance. (Clin Exp Optom 1996; 80: 1: 1–12)     

视网膜色素变性的研究进展

视网膜色素变性(retinitis pigmentosa,RP)是常见的与遗传相关的致盲性眼病之一,随着人类基因图谱的成功建立,它成为近几年国内外基础医学和临床医学共同的研究热点。本文回顾十余年来国内外特别是国外相关文献,对视网膜色素变性的发病机制、治疗方法的研究进展作一综述。     

中国人一个显性视网膜色素变性家系8号染色体连锁分析

目的用连锁分析法对中国人一个显性视网膜色素变性家系8号染色体进行分析，确定致病基因。方法随机选取8号染色体RP1基因上下约10厘摩(cm)范围内的10对微卫星标记(marker)，确立单倍体型，用两点法计算最大优势对数(LOD SCORE)值。结果所选微卫星标记与该家系表型间最大LOD值小于1。结论RP1基因可能为该家系的非致病性基因，用连锁分析法进行致病基因排除对最终确立致病基因所在染色体的范围具有重要的价值。     

常染色体显性遗传视网膜色素变性致病基因的研究进展

视网膜色素变性（retinitis pigmentosa,RP)是常见的遗传性视网膜变性疾病，它具有高度的遗传异质性，有不同的遗传方式和临床表型，目前已发现常染色体显性遗传型视网膜色素变性（autosomal dominant retinitis pigmentosa,ADRP)的12种基因，其中已被克隆的有RHO，RDS，ROM1，RP1，NRL及CRX，未被克隆的有RP9，RP10，RP11，RP13，RP17及RP18，本文主要介绍与ADRP相关的几个基因的最新研究进展。     

视网膜色素变性的眼底血流变化研究现状

视网膜色素变性(retinitis pigmentosa,RP)是一种临床常见的遗传性致盲性眼底病,多由夜盲起病,经过几十年进行性视力下降致最终失明.其病理特点为原发性感光细胞凋亡长期发展最终导致视网膜色素上皮和内层视网膜结构及功能损伤.多个研究表明RP早期出现眼底血流减少.原因可能是原发性血管功能失调和血浆内皮素-1升高.目前有多种可有效评估视网膜血流情况的方法.针对改善眼底血流的治疗能够在一定程度上延缓RP病情的进展.对于眼底血流和RP关系的认识加深有助于寻找新的有效治疗RP的方法.     

视网膜色素变性患者视锥杆细胞同源盒基因突变的研究

目的:研究视锥杆细胞同源盒基因(CRX)在宁夏地区视网膜色素变性(rentinitis pigmentosa,RP)患者中的突变频率及特征,并进一步探讨其在RP发病机制中潜在的机制。方法:运用聚合酶链反应(PCR)和直接测序方法,对100例RP患者(包括18例ADRP患者,15例ARRP患者,67例SRP患者)进行了CRX基因全编码区序列突变的检测,运用多因素分析研究CRX基因突变位点对RP的作用。结果:在100例RP患者CRX基因上共检测出5个变异位点,其中p.Leu78Leu,p.Ala92Ala和p.Thr187Ile为新发现的突变。其余位点突变均证实为CRX基因的多态性。p.Thr187Ile突变位点仅在2例ARRP患者身上检出,在正常对照组未发现该位点突变。结论:宁夏地区RP患者中,CRX基因的突变率低于其他人群中(小于1%)。p.Thr187Ile不是RP的致病性突变,但它是否可能通过影响其它基因的表达,增加常染色体显性遗传视网膜色素变性(ARRP)的发生,有待于进一步研究。